There is a conventionally known air conditioner for a vehicle in which rear vent doors and foot doors with independently controlled door opening degrees are provided respectively in rear vent outlet paths and foot outlet paths formed in an air conditioner casing (see Japanese Patent Application Laid-Open (JP-A) No. 6-92135, for example).
There is also a known air conditioner for a vehicle in which doors are not provided in rear vent outlet paths formed in an air conditioner casing and foot doors are provided only in foot outlet paths (see JP-A No. 9-267620, for example).
In the air conditioner for the vehicle described in JP-A No. 6-92135, however, the rear vent doors and the foot doors with independently controlled door opening degrees are provided respectively in the rear vent outlet paths and the foot outlet paths and therefore special door links need to be provided to the respective doors, which increases cost and impairs space-saving property.
In the air conditioner for the vehicle described in JP-A No. 9-267620, the foot doors are provided only in the foot outlet paths. Therefore, if the rear vent outlet paths and the foot outlet paths branching out via an air mix chamber for mixing cold air and hot air are provided in the air conditioner unit, foot outlet air distribution amounts become insufficient when a bi-level mode or a defroster/foot mode for carrying out both foot outlet air distribution and rear vent outlet air distribution is selected.
In other words, if a plurality of outlet paths branch out via the air mix chamber, amounts of air distribution to the respective outlet paths are determined by path resistances. The path resistances are higher in the foot outlet paths curved in complicated manners than in the rear vent outlet paths curved in simple manners. Therefore, even if the foot doors are fully open, amounts of air distribution to the rear vent outlet paths having the lower path resistances become greater. As a result, foot outlet air distribution amounts become relatively insufficient.
The present invention has been made with the above problems in view and it is an object of the invention to provide an air conditioner for a vehicle, advantageous in cost and space-saving property, and capable of adjusting foot outlet air distribution amounts to proper and sufficient amounts when a mode for carrying out foot outlet air distribution and rear vent outlet air distribution is selected.